The present invention relates to brushless d-c motors having electric commutation circuits in which the motor is connected to the commutation circuit by a mating connector.
Electrically commutated d-c motors are often connected to the associated control or commutation circuit via plug connectors. For economic reasons, simple plug connectors are usually chosen in which the connector pins and the connector jacks are arranged symmetrically about the connector axis, there being at least two configurations in which the plug and jack of the connector may be joined. Such plug connectors are simple and inexpensive. However, there exists the danger of damaging or destroying the motor and/or the electric commutation circuit if the two connector parts are not joined together in the correct configuration. One way of preventing damage to, or destruction of, the motor and/or circuit is to provide means in the connector to prevent the connector parts from being incorrectly joined. However, this increases the cost of the connector considerably.
In motors with simple commutation circuits, the direction of rotation of the motor is determined as a rule in the factory. If it is desired, however, to change the direction of rotation of the motor, appropriate changes must be made in the motor and/or the commutation circuit, such as reversing the polarity of the windings or of the control circuit, and the like. This is usually accomplished by resoldering wire jumpers, resoldering the leads of the stator windings or the like. The possibility of damaging or destroying the motor and/or the circuit, however, still exists because the connections can be made incorrectly.